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/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.net.util; import java.io.UnsupportedEncodingException; import java.math.BigInteger; /** * Provides Base64 encoding and decoding as defined by RFC 2045. * * <p> * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein. * </p> * <p> * The class can be parameterized in the following manner with various constructors: * <ul> * <li>URL-safe mode: Default off.</li> * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of * 4 in the encoded data. * <li>Line separator: Default is CRLF ("\r\n")</li> * </ul> * </p> * <p> * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). * </p> * * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> * @author Apache Software Foundation * @since 2.2 * @version $Id: Base64.java 1489533 2013-06-04 17:49:00Z sebb $ */ public class Base64 { private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2; private static final int DEFAULT_BUFFER_SIZE = 8192; /** * Chunk size per RFC 2045 section 6.8. * * <p> * The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any * equal signs. * </p> * * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a> */ static final int CHUNK_SIZE = 76; /** * Chunk separator per RFC 2045 section 2.1. * * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a> */ private static final byte[] CHUNK_SEPARATOR = { '\r', '\n' }; private static final byte[] EMPTY_BYTE_ARRAY = new byte[0]; /** * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet" * equivalents as specified in Table 1 of RFC 2045. * * Thanks to "commons" project in ws.apache.org for this code. * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ */ private static final byte[] STANDARD_ENCODE_TABLE = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; /** * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and / * changed to - and _ to make the encoded Base64 results more URL-SAFE. * This table is only used when the Base64's mode is set to URL-SAFE. */ private static final byte[] URL_SAFE_ENCODE_TABLE = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_' }; /** * Byte used to pad output. */ private static final byte PAD = '='; /** * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified in * Table 1 of RFC 2045) into their 6-bit positive integer equivalents. Characters that are not in the Base64 * alphabet but fall within the bounds of the array are translated to -1. * * Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both * URL_SAFE and STANDARD base64. (The encoder, on the other hand, needs to know ahead of time what to emit). * * Thanks to "commons" project in ws.apache.org for this code. * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ */ private static final byte[] DECODE_TABLE = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 }; /** Mask used to extract 6 bits, used when encoding */ private static final int MASK_6BITS = 0x3f; /** Mask used to extract 8 bits, used in decoding base64 bytes */ private static final int MASK_8BITS = 0xff; // The static final fields above are used for the original static byte[] methods on Base64. // The private member fields below are used with the new streaming approach, which requires // some state be preserved between calls of encode() and decode(). /** * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch * between the two modes. */ private final byte[] encodeTable; /** * Line length for encoding. Not used when decoding. A value of zero or less implies no chunking of the base64 * encoded data. */ private final int lineLength; /** * Line separator for encoding. Not used when decoding. Only used if lineLength > 0. */ private final byte[] lineSeparator; /** * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. * <code>decodeSize = 3 + lineSeparator.length;</code> */ private final int decodeSize; /** * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. * <code>encodeSize = 4 + lineSeparator.length;</code> */ private final int encodeSize; /** * Buffer for streaming. */ private byte[] buffer; /** * Position where next character should be written in the buffer. */ private int pos; /** * Position where next character should be read from the buffer. */ private int readPos; /** * Variable tracks how many characters have been written to the current line. Only used when encoding. We use it to * make sure each encoded line never goes beyond lineLength (if lineLength > 0). */ private int currentLinePos; /** * Writes to the buffer only occur after every 3 reads when encoding, an every 4 reads when decoding. This variable * helps track that. */ private int modulus; /** * Boolean flag to indicate the EOF has been reached. Once EOF has been reached, this Base64 object becomes useless, * and must be thrown away. */ private boolean eof; /** * Place holder for the 3 bytes we're dealing with for our base64 logic. Bitwise operations store and extract the * base64 encoding or decoding from this variable. */ private int x; /** * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. * <p> * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. * </p> * * <p> * When decoding all variants are supported. * </p> */ public Base64() { this(false); } /** * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. * <p> * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. * </p> * * <p> * When decoding all variants are supported. * </p> * * @param urlSafe * if <code>true</code>, URL-safe encoding is used. In most cases this should be set to * <code>false</code>. * @since 1.4 */ public Base64(boolean urlSafe) { this(CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); } /** * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. * <p> * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is * STANDARD_ENCODE_TABLE. * </p> * <p> * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. * </p> * <p> * When decoding all variants are supported. * </p> * * @param lineLength * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. * @since 1.4 */ public Base64(int lineLength) { this(lineLength, CHUNK_SEPARATOR); } /** * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. * <p> * When encoding the line length and line separator are given in the constructor, and the encoding table is * STANDARD_ENCODE_TABLE. * </p> * <p> * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. * </p> * <p> * When decoding all variants are supported. * </p> * * @param lineLength * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. * @param lineSeparator * Each line of encoded data will end with this sequence of bytes. * @throws IllegalArgumentException * Thrown when the provided lineSeparator included some base64 characters. * @since 1.4 */ public Base64(int lineLength, byte[] lineSeparator) { this(lineLength, lineSeparator, false); } /** * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. * <p> * When encoding the line length and line separator are given in the constructor, and the encoding table is * STANDARD_ENCODE_TABLE. * </p> * <p> * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. * </p> * <p> * When decoding all variants are supported. * </p> * * @param lineLength * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. * @param lineSeparator * Each line of encoded data will end with this sequence of bytes. * @param urlSafe * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode * operations. Decoding seamlessly handles both modes. * @throws IllegalArgumentException * The provided lineSeparator included some base64 characters. That's not going to work! * @since 1.4 */ public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) { if (lineSeparator == null) { lineLength = 0; // disable chunk-separating lineSeparator = EMPTY_BYTE_ARRAY; // this just gets ignored } this.lineLength = lineLength > 0 ? (lineLength / 4) * 4 : 0; this.lineSeparator = new byte[lineSeparator.length]; System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); if (lineLength > 0) { this.encodeSize = 4 + lineSeparator.length; } else { this.encodeSize = 4; } this.decodeSize = this.encodeSize - 1; if (containsBase64Byte(lineSeparator)) { String sep = newStringUtf8(lineSeparator); throw new IllegalArgumentException("lineSeperator must not contain base64 characters: [" + sep + "]"); } this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; } /** * Returns our current encode mode. True if we're URL-SAFE, false otherwise. * * @return true if we're in URL-SAFE mode, false otherwise. * @since 1.4 */ public boolean isUrlSafe() { return this.encodeTable == URL_SAFE_ENCODE_TABLE; } /** * Returns true if this Base64 object has buffered data for reading. * * @return true if there is Base64 object still available for reading. */ boolean hasData() { return this.buffer != null; } /** * Returns the amount of buffered data available for reading. * * @return The amount of buffered data available for reading. */ int avail() { return buffer != null ? pos - readPos : 0; } /** Doubles our buffer. */ private void resizeBuffer() { if (buffer == null) { buffer = new byte[DEFAULT_BUFFER_SIZE]; pos = 0; readPos = 0; } else { byte[] b = new byte[buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR]; System.arraycopy(buffer, 0, b, 0, buffer.length); buffer = b; } } /** * Extracts buffered data into the provided byte[] array, starting at position bPos, up to a maximum of bAvail * bytes. Returns how many bytes were actually extracted. * * @param b * byte[] array to extract the buffered data into. * @param bPos * position in byte[] array to start extraction at. * @param bAvail * amount of bytes we're allowed to extract. We may extract fewer (if fewer are available). * @return The number of bytes successfully extracted into the provided byte[] array. */ int readResults(byte[] b, int bPos, int bAvail) { if (buffer != null) { int len = Math.min(avail(), bAvail); if (buffer != b) { System.arraycopy(buffer, readPos, b, bPos, len); readPos += len; if (readPos >= pos) { buffer = null; } } else { // Re-using the original consumer's output array is only // allowed for one round. buffer = null; } return len; } return eof ? -1 : 0; } /** * Sets the streaming buffer. This is a small optimization where we try to buffer directly to the consumer's output * array for one round (if the consumer calls this method first) instead of starting our own buffer. * * @param out * byte[] array to buffer directly to. * @param outPos * Position to start buffering into. * @param outAvail * Amount of bytes available for direct buffering. */ void setInitialBuffer(byte[] out, int outPos, int outAvail) { // We can re-use consumer's original output array under // special circumstances, saving on some System.arraycopy(). if (out != null && out.length == outAvail) { buffer = out; pos = outPos; readPos = outPos; } } /** * <p> * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last * remaining bytes (if not multiple of 3). * </p> * <p> * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ * </p> * * @param in * byte[] array of binary data to base64 encode. * @param inPos * Position to start reading data from. * @param inAvail * Amount of bytes available from input for encoding. */ void encode(byte[] in, int inPos, int inAvail) { if (eof) { return; } // inAvail < 0 is how we're informed of EOF in the underlying data we're // encoding. if (inAvail < 0) { eof = true; if (buffer == null || buffer.length - pos < encodeSize) { resizeBuffer(); } switch (modulus) { case 1: buffer[pos++] = encodeTable[(x >> 2) & MASK_6BITS]; buffer[pos++] = encodeTable[(x << 4) & MASK_6BITS]; // URL-SAFE skips the padding to further reduce size. if (encodeTable == STANDARD_ENCODE_TABLE) { buffer[pos++] = PAD; buffer[pos++] = PAD; } break; case 2: buffer[pos++] = encodeTable[(x >> 10) & MASK_6BITS]; buffer[pos++] = encodeTable[(x >> 4) & MASK_6BITS]; buffer[pos++] = encodeTable[(x << 2) & MASK_6BITS]; // URL-SAFE skips the padding to further reduce size. if (encodeTable == STANDARD_ENCODE_TABLE) { buffer[pos++] = PAD; } break; default: break; // other values ignored } if (lineLength > 0 && pos > 0) { System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); pos += lineSeparator.length; } } else { for (int i = 0; i < inAvail; i++) { if (buffer == null || buffer.length - pos < encodeSize) { resizeBuffer(); } modulus = (++modulus) % 3; int b = in[inPos++]; if (b < 0) { b += 256; } x = (x << 8) + b; if (0 == modulus) { buffer[pos++] = encodeTable[(x >> 18) & MASK_6BITS]; buffer[pos++] = encodeTable[(x >> 12) & MASK_6BITS]; buffer[pos++] = encodeTable[(x >> 6) & MASK_6BITS]; buffer[pos++] = encodeTable[x & MASK_6BITS]; currentLinePos += 4; if (lineLength > 0 && lineLength <= currentLinePos) { System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); pos += lineSeparator.length; currentLinePos = 0; } } } } } /** * <p> * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" * call is not necessary when decoding, but it doesn't hurt, either. * </p> * <p> * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in, * garbage-out philosophy: it will not check the provided data for validity. * </p> * <p> * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ * </p> * * @param in * byte[] array of ascii data to base64 decode. * @param inPos * Position to start reading data from. * @param inAvail * Amount of bytes available from input for encoding. */ void decode(byte[] in, int inPos, int inAvail) { if (eof) { return; } if (inAvail < 0) { eof = true; } for (int i = 0; i < inAvail; i++) { if (buffer == null || buffer.length - pos < decodeSize) { resizeBuffer(); } byte b = in[inPos++]; if (b == PAD) { // We're done. eof = true; break; } else { if (b >= 0 && b < DECODE_TABLE.length) { int result = DECODE_TABLE[b]; if (result >= 0) { modulus = (++modulus) % 4; x = (x << 6) + result; if (modulus == 0) { buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS); buffer[pos++] = (byte) (x & MASK_8BITS); } } } } } // Two forms of EOF as far as base64 decoder is concerned: actual // EOF (-1) and first time '=' character is encountered in stream. // This approach makes the '=' padding characters completely optional. if (eof && modulus != 0) { x = x << 6; switch (modulus) { case 2: x = x << 6; buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); break; case 3: buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS); break; default: break; // other values ignored } } } /** * Returns whether or not the <code>octet</code> is in the base 64 alphabet. * * @param octet * The value to test * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise. * @since 1.4 */ public static boolean isBase64(byte octet) { return octet == PAD || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1); } /** * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the * method treats whitespace as valid. * * @param arrayOctet * byte array to test * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; * false, otherwise */ public static boolean isArrayByteBase64(byte[] arrayOctet) { for (int i = 0; i < arrayOctet.length; i++) { if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) { return false; } } return true; } /** * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. * * @param arrayOctet * byte array to test * @return <code>true</code> if any byte is a valid character in the Base64 alphabet; false herwise */ private static boolean containsBase64Byte(byte[] arrayOctet) { for (byte element : arrayOctet) { if (isBase64(element)) { return true; } } return false; } /** * Encodes binary data using the base64 algorithm but does not chunk the output. * * @param binaryData * binary data to encode * @return byte[] containing Base64 characters in their UTF-8 representation. */ public static byte[] encodeBase64(byte[] binaryData) { return encodeBase64(binaryData, false); } /** * Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF. * <p> * For a non-chunking version, see {@link #encodeBase64StringUnChunked(byte[])}. * * @param binaryData * binary data to encode * @return String containing Base64 characters. * @since 1.4 */ public static String encodeBase64String(byte[] binaryData) { return newStringUtf8(encodeBase64(binaryData, true)); } /** * Encodes binary data using the base64 algorithm, without using chunking. * <p> * For a chunking version, see {@link #encodeBase64String(byte[])}. * * @param binaryData * binary data to encode * @return String containing Base64 characters. * @since 3.2 */ public static String encodeBase64StringUnChunked(byte[] binaryData) { return newStringUtf8(encodeBase64(binaryData, false)); } /** * Encodes binary data using the base64 algorithm. * * @param binaryData * binary data to encode * @param useChunking whether to split the output into chunks * @return String containing Base64 characters. * @since 3.2 */ public static String encodeBase64String(byte[] binaryData, boolean useChunking) { return newStringUtf8(encodeBase64(binaryData, useChunking)); } /** * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The * url-safe variation emits - and _ instead of + and / characters. * * @param binaryData * binary data to encode * @return byte[] containing Base64 characters in their UTF-8 representation. * @since 1.4 */ public static byte[] encodeBase64URLSafe(byte[] binaryData) { return encodeBase64(binaryData, false, true); } /** * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The * url-safe variation emits - and _ instead of + and / characters. * * @param binaryData * binary data to encode * @return String containing Base64 characters * @since 1.4 */ public static String encodeBase64URLSafeString(byte[] binaryData) { return newStringUtf8(encodeBase64(binaryData, false, true)); } /** * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks * * @param binaryData * binary data to encode * @return Base64 characters chunked in 76 character blocks */ public static byte[] encodeBase64Chunked(byte[] binaryData) { return encodeBase64(binaryData, true); } /** * Decodes a String containing containing characters in the Base64 alphabet. * * @param pArray * A String containing Base64 character data * @return a byte array containing binary data * @since 1.4 */ public byte[] decode(String pArray) { return decode(getBytesUtf8(pArray)); } private byte[] getBytesUtf8(String pArray) { try { return pArray.getBytes("UTF8"); } catch (UnsupportedEncodingException e) { throw new RuntimeException(e); } } /** * Decodes a byte[] containing containing characters in the Base64 alphabet. * * @param pArray * A byte array containing Base64 character data * @return a byte array containing binary data */ public byte[] decode(byte[] pArray) { reset(); if (pArray == null || pArray.length == 0) { return pArray; } long len = (pArray.length * 3) / 4; byte[] buf = new byte[(int) len]; setInitialBuffer(buf, 0, buf.length); decode(pArray, 0, pArray.length); decode(pArray, 0, -1); // Notify decoder of EOF. // Would be nice to just return buf (like we sometimes do in the encode // logic), but we have no idea what the line-length was (could even be // variable). So we cannot determine ahead of time exactly how big an // array is necessary. Hence the need to construct a 2nd byte array to // hold the final result: byte[] result = new byte[pos]; readResults(result, 0, result.length); return result; } /** * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. * * @param binaryData * Array containing binary data to encode. * @param isChunked * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks * @return Base64-encoded data. * @throws IllegalArgumentException * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} */ public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) { return encodeBase64(binaryData, isChunked, false); } /** * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. * * @param binaryData * Array containing binary data to encode. * @param isChunked * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks * @param urlSafe * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. * @return Base64-encoded data. * @throws IllegalArgumentException * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} * @since 1.4 */ public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) { return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE); } /** * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. * * @param binaryData * Array containing binary data to encode. * @param isChunked * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks * @param urlSafe * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. * @param maxResultSize * The maximum result size to accept. * @return Base64-encoded data. * @throws IllegalArgumentException * Thrown when the input array needs an output array bigger than maxResultSize * @since 1.4 */ public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) { if (binaryData == null || binaryData.length == 0) { return binaryData; } long len = getEncodeLength(binaryData, isChunked ? CHUNK_SIZE : 0, isChunked ? CHUNK_SEPARATOR : EMPTY_BYTE_ARRAY); if (len > maxResultSize) { throw new IllegalArgumentException("Input array too big, the output array would be bigger (" + len + ") than the specified maxium size of " + maxResultSize); } Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe); return b64.encode(binaryData); } /** * Decodes a Base64 String into octets * * @param base64String * String containing Base64 data * @return Array containing decoded data. * @since 1.4 */ public static byte[] decodeBase64(String base64String) { return new Base64().decode(base64String); } /** * Decodes Base64 data into octets * * @param base64Data * Byte array containing Base64 data * @return Array containing decoded data. */ public static byte[] decodeBase64(byte[] base64Data) { return new Base64().decode(base64Data); } /** * Checks if a byte value is whitespace or not. * * @param byteToCheck * the byte to check * @return true if byte is whitespace, false otherwise */ private static boolean isWhiteSpace(byte byteToCheck) { switch (byteToCheck) { case ' ': case '\n': case '\r': case '\t': return true; default: return false; } } /** * Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet. * * @param pArray * a byte array containing binary data * @return A String containing only Base64 character data * @since 1.4 */ public String encodeToString(byte[] pArray) { return newStringUtf8(encode(pArray)); } private static String newStringUtf8(byte[] encode) { String str = null; try { str = new String(encode, "UTF8"); } catch (UnsupportedEncodingException ue) { throw new RuntimeException(ue); } return str; } /** * Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet. * * @param pArray * a byte array containing binary data * @return A byte array containing only Base64 character data */ public byte[] encode(byte[] pArray) { reset(); if (pArray == null || pArray.length == 0) { return pArray; } long len = getEncodeLength(pArray, lineLength, lineSeparator); byte[] buf = new byte[(int) len]; setInitialBuffer(buf, 0, buf.length); encode(pArray, 0, pArray.length); encode(pArray, 0, -1); // Notify encoder of EOF. // Encoder might have resized, even though it was unnecessary. if (buffer != buf) { readResults(buf, 0, buf.length); } // In URL-SAFE mode we skip the padding characters, so sometimes our // final length is a bit smaller. if (isUrlSafe() && pos < buf.length) { byte[] smallerBuf = new byte[pos]; System.arraycopy(buf, 0, smallerBuf, 0, pos); buf = smallerBuf; } return buf; } /** * Pre-calculates the amount of space needed to base64-encode the supplied array. * * @param pArray byte[] array which will later be encoded * @param chunkSize line-length of the output (<= 0 means no chunking) between each * chunkSeparator (e.g. CRLF). * @param chunkSeparator the sequence of bytes used to separate chunks of output (e.g. CRLF). * * @return amount of space needed to encoded the supplied array. Returns * a long since a max-len array will require Integer.MAX_VALUE + 33%. */ private static long getEncodeLength(byte[] pArray, int chunkSize, byte[] chunkSeparator) { // base64 always encodes to multiples of 4. chunkSize = (chunkSize / 4) * 4; long len = (pArray.length * 4) / 3; long mod = len % 4; if (mod != 0) { len += 4 - mod; } if (chunkSize > 0) { boolean lenChunksPerfectly = len % chunkSize == 0; len += (len / chunkSize) * chunkSeparator.length; if (!lenChunksPerfectly) { len += chunkSeparator.length; } } return len; } // Implementation of integer encoding used for crypto /** * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature * * @param pArray * a byte array containing base64 character data * @return A BigInteger * @since 1.4 */ public static BigInteger decodeInteger(byte[] pArray) { return new BigInteger(1, decodeBase64(pArray)); } /** * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature * * @param bigInt * a BigInteger * @return A byte array containing base64 character data * @throws NullPointerException * if null is passed in * @since 1.4 */ public static byte[] encodeInteger(BigInteger bigInt) { if (bigInt == null) { throw new NullPointerException("encodeInteger called with null parameter"); } return encodeBase64(toIntegerBytes(bigInt), false); } /** * Returns a byte-array representation of a <code>BigInteger</code> without sign bit. * * @param bigInt * <code>BigInteger</code> to be converted * @return a byte array representation of the BigInteger parameter */ static byte[] toIntegerBytes(BigInteger bigInt) { int bitlen = bigInt.bitLength(); // round bitlen bitlen = ((bitlen + 7) >> 3) << 3; byte[] bigBytes = bigInt.toByteArray(); if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) { return bigBytes; } // set up params for copying everything but sign bit int startSrc = 0; int len = bigBytes.length; // if bigInt is exactly byte-aligned, just skip signbit in copy if ((bigInt.bitLength() % 8) == 0) { startSrc = 1; len--; } int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec byte[] resizedBytes = new byte[bitlen / 8]; System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len); return resizedBytes; } /** * Resets this Base64 object to its initial newly constructed state. */ private void reset() { buffer = null; pos = 0; readPos = 0; currentLinePos = 0; modulus = 0; eof = false; } // Getters for use in testing int getLineLength() { return lineLength; } byte[] getLineSeparator() { return lineSeparator.clone(); } }